Heat oil in a large oven-proof skillet over medium-high. Add onion and cook 3-5 minutes, adding garlic toward the end. Saute for 1 minute. Add ground turkey and cook for additional 5-6 minutes, stirring to crumble, until meat mixture is golden brown. Remove from heat.
Cook ramen noodles according to package directions (about 3-5 mintues) in lightly salted water. Drain and rinse with cold water.
Stir in marinara sauce, oregano, and vinegar into the meat mixture; cook 5 minutes. Add ramen noodles; gently mix. Sprinkle 1 cup of each of the 3 cheeses into meat mixture. Sprinkle with remaining cheeses.
Bake at 375 degrees for 15-20 minutes; cheese will be bubbly and melted. Sprinkle with fresh oregano; serve!